1. Field
Example embodiments relate to a connection structure for a circuit board using a solder bump to connect two circuit boards.
2. Description of the Related Art
A printed circuit board (PCB) may serve to connect a plurality of electronic devices in a certain framework and is widely employed in a number of electronic products including, for example, electrical home appliances, e.g., digital TVs and advanced telecommunication devices.
In certain electronic devices, for example, a mobile phone or a digital camera, a thin folding type flexible printed circuit (FPC) is used for fabrication of an internal wiring. With increased miniaturization as well as enlargement of a movable part in the mobile phone, such FPC is increasingly used. When connecting the FPC to a rigid substrate used as a main board, a connector or an anisotropic conductive film (ACF) may be used.
Connectors are well known and widely used to provide a connection between boards and, in particular, may have a merit of repetitive attachment/detachment of FPC. However, it is difficult to employ connectors with complicated shapes in automatic connections thereof and to reduce a size of the connector due to three-dimensional space occupied thereby.
An ACF is a thermosetting resin film containing conductive single particles. In adhering the ACF at a terminal part of one substrate and laminating a terminal of another substrate over the adhered ACF, the laminate is pressed so that a conductive terminal is inserted between two opposite electrode faces, thereby guaranteeing electrical through-connection between terminals via the inserted conductive terminal. The ACF connection may have merits in connection of narrow pitches. However, as the conductive particle connects with the terminals, it may exhibit higher resistance at connection parts as compared to soldering connection. Because the resin hardens over time, the resin is duly removed using a particular solvent. Accordingly, the ACF described above has problems of increased time and/or cost, as compared to repairing of soldered products.